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86670028f7
The value of the MVFR1 (Media and VFP Feature Register 1) register for the Cortex-A8 appears to be incorrect (according to the TRM, DDI0344K), with the "full denormal arithmetic" and "propagation of NaN" fields holding both 0 instead of both 1. I had a go tracing the history of the use of this value, and it seems it's always just been wrong in QEMU: maybe it was derived from early documentation, or guessed based on the use of a "VFP Lite" implementation in the Cortex-A8. Depending on the startup/early-boot code in use, this can manifest as failure to perform denormal arithmetic properly: in our case, selecting a Cortex-A8 CPU when using QEMU as an instruction-set simulator for bare-metal GCC testing caused tests using denormal arithmetic to fail. Problems might be masked (or not occur) when using a full OS kernel with suitable trap handlers (I'm not sure). Backports commit 0f1944735b6bac810b067e8a7a5154744536fd59 from qemu |
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arm_ldst.h | ||
cpu-qom.h | ||
cpu.c | ||
cpu.h | ||
cpu64.c | ||
crypto_helper.c | ||
helper-a64.c | ||
helper-a64.h | ||
helper.c | ||
helper.h | ||
internals.h | ||
iwmmxt_helper.c | ||
kvm-consts.h | ||
Makefile.objs | ||
neon_helper.c | ||
op_addsub.h | ||
op_helper.c | ||
psci.c | ||
translate-a64.c | ||
translate.c | ||
translate.h | ||
unicorn.h | ||
unicorn_aarch64.c | ||
unicorn_arm.c |